In recent years, with the spread of smart phones and tablet devices, traffic in mobile transmission has continued to exponentially increase and is expected to increase further in the future. As one of measures for the increase in wireless traffic, increasing the bandwidth is being considered. In Long Term Evolution (LTE) or LTE-Advanced (LTE-A) by 3rd Generation Partnership Project (3GPP), carrier aggregation that realizes broadband by bundling a plurality of component carriers is being studied. The carrier aggregation is described in NPL 1. In a method of NPL 1, a system bandwidth of a single component carrier is set to maximum 20 MHz, and the maximum number of component carriers assigned to a single terminal device is set to five.